Irregular bleeding after heavy period?

My periods are usually five days long in a 27 day cycle. This past period (which I assumed I'd gotten off yesterday) was part of a 18 day cycle. It came super early which threw me off.

Anyways, my period came 10/1 and ended 10/5. Today (10/6) though I've experienced weird blood mixed in with what looks like cervical mucus. I have heavy periods and this was no exception, but this period was so heavy it caused dizzy spells and tiredness.

I'd say it's normal, but with it coming so early and now this weird bloody discharge I'm scared. I have an OBGYN appointment Thursday, so hopefully I'll be able to talk to her and get this cleared up.

I've attached a pic of today's bloody discharge. Sorry if it grosses you out, but we're all females!

(Forgot to add: the last time I was sexually active was August 19 while on my period. I had a period in September, so no chance of pregnancy.)